In recent years, portable consumer electronic wireless communications devices such as smart phones, tablet computers, and laptop computers have been equipped with a variety of integrated digital subsystems. One example of such a subsystem is an integrated digital camera. The cameras used in such devices are often in the form of a module that includes, for example, a charge coupled device (CCD) imaging sensor or a complementary metal oxide semiconductor (CMOS) imaging sensor that is in a compact package together with its optical system. Camera modules having either type of imaging sensor move photodetected charge as a mass of digital signals sequentially, at a rate synchronized with a clock signal that is typically generated from a source outside the camera module. The clock signal that is input to the camera module and the digital data signal that is output in synchronism with the clock signal contain harmonic components that may interfere with the operation of other integrated subsystems such as the radio communications circuitry. In the case where a harmonic component coincides with the radio communication frequency band, the radio communication would be adversely affected.
With the recent trend toward wireless communications devices of increasingly smaller size, the radio communications circuitry, the camera module, and the camera clock signal generator are often arranged within the housing or body of the device in close proximity to each other. For instance, in order to have a thinner body, the camera module is not mounted directly on a main logic board, but rather may be connected to the main logic board and the clock signal generator through a flexible circuit. In this case, the radiation noise of the harmonic components of the clock signal and the digital data signal may be released from the flexible circuit and interfere with radio communications. On the other hand, radio communications frequencies may be picked up by the flexible circuit and interfere with the camera clock signal and the digital data signal that is transmitted to and from the camera module through the flexible circuit.